Supercharger



A. T. GREGORY EI'AL. SUPERCHARGER File d Sept. 17, 1942 s Sheets-Shet 1i IIIIIIIIIIIIIII Dec. 7, 1943. A. 1-. GREGORY E AL 2,336,010

' SUPERCI-IARGER Filed Sept. 17, 1942 s Shets-Shet 2 INVENTORS PatentedDec. 7, 1943 SUPERCHARGER Alfred '1. Grego y, Massapequa, and Eugene W.Wasielewski, Westbury, N. Y., assignors to Fairchild Engine and AirplaneCorporation, Farmlngdale, N. Y., a corporation 01' Maryland ApplicationSeptember 1'1, 1942, Serial No. (or. earnin 8 illaim's.

This invention relates to superchargers and has particular reference tosuperchargers for in ternal combustion engines of the aeronautical cass.although the invention'is not limited to that class. l

As generally arranged, superchargers for aeronautical engines. areeither driven directly by the engine or by an engine exhaust turbine,and their speed and consequent volumetric output is govemed eithermanually or automatically, in accordance with the requirements of theengine.

' Various means are also provided for controlling the pressure riseratio at different altitudes, including automatic regulators responsiveto altietude changes for adjusting impeller speeds, as shown, forexample, in Gregory Patent No. 2,187,737; arrangements including-adjustable vanes in the intake for varying the directional relationbetween the intake fluid and that in the impeller, as shown for examplein Szydlowski and n 'Planiol Patent No. 2,210,155, and the like.

In accordance with the present invention, a

simple and effective arrangement is provided for regulatmg thepressurerise ratio of an engine tire means for obtaining all variationsin pressure rise ratio that are required during the most severeoperating conditions of an engine, and in a simple manner requiring aminimum of operating mechanism. e

For a more complete understanding of the invention, reference may be hadto the accompanying drawings, in which:

Figure l is an axial section of a supercharger equipped with thepressure ratio controlling means of this invention, as seen along theline l-l of'Fig. 2;

Fig. 2 is a transverse section. through one of the two fluid intakescrolls, as seen along the line 2--2 of Fig. i;

Fig. 3 is a transverse section through the other fluid intake scroll asseen along the line 33 from one duct swirls in the direction of impellervided when either of the ducts is fully closed.-

The valve may be of the sleeve, butterfly,- slide B partially or anyequivalent type of valve controlled manually or automatically inaccordance titude changes, and the like.

It will be seen that the supercharger control of the present inventionprovides a very effecwith alof Fig. l; a

Fig; 4 is a partially schematic elevation of the supercharger arrangedfor automatic pressure rise ratio control in accordance with altitudechanges;

Fig. 5 is a view in section showing supercharger provided with amodified form of control valve;

and

Fig. 6 is an end view of a supercharger provided with still another typeof control valve system.

Referring to Fig. '1 of the drawings, numeral ill designates thesupercharger, which may be of the aeronautical type, having a housing Hprovided with the usual diffuser scroll l2, discharge pipe I2 leading tothe engine, andthe impeller it of the bent blade type whose shaft it isdriven from any suitable source of power, such as the engine, an exhaustgas turbine, or the like.

The housing II is preferably provided with a tubular axial extension l5enclosed within two separate intake scrolls l6 and [1, having the commonseparating partition l8.

Scroll. i6 is directed in the direction of the supercharger diffuserscroll l2 and hence is complementary thereto in that it imparts a swirlto the intake fluid in the same direction that the impeller I3 isdriven, i. e., in a counter-clockwise direction, as seen in Fig. 3.Complementary scroll I6 is supplied by duct IS with air, or fuel-airmixture, depending upon whether or not the fuel supply or carburetor isahead of the supercharger, or other fluid, according to requirements.

Scroll I1 is directed oppositely toisupercharger diffuser scroll l2, asbest shown in Fig. 2, and hence the swirl that it imparts to the intakefluid is in opposition to the direction 011 the impeller supplied withair, combustible mixture, or other fluid by duct 20.

Journalled within supercharger casing extension I5 is a dual sleevevalve 2| having an axial stud or stub shaft 22 extending through the endwall 23 of the casing extension l5 and fitted with a crank or lever 24whereby the sleeve valve 2| may be rotated about its axis, as by meansof .alink25.

'I'he'wall of sleeve valve 2| opposite complementary intake scroll l 6is pierced by rectangular slots 26 adapted to register withcorresponding slots 26' of substantially equal size and shape in thehousing extension l5.

Similarly, the wall of sleeve valve 2| opposite the opposition intakescroll I1 is pierced by rectangular slots 21 adapted to register withcorresponding slots 21 of substantially equal size and shape in housingextension 5. However, slots 21 in sleeve valve 2| are staggered ordisplaced angularly from slots 26, the latter lying diagonally betweenslots 21, as is best seenin Fig. 1. Consequently, when sleeve valve 2|is adjusted so that the complementary intake scroll slots 26 are fullyclosed, as shown in Fig. 3, the opposition intake scroll slots 21 are inregistry with slots 21' and are fully open, and vice versa.

,As shown in Fig. 2, the longitudinal edges of slots 21, 21' areinclined in the direction of movement of the fluid in opposition intakescroll |1, so that when the slots are in registry this inclination oftheir edges maintains and aids in imparting the desired clockwise swirl,as seen in Fig. 2. Likewise, as shown in Fig. 3, the longitudinal edgesof the slots 26, 26' are inclined in the direction of movement of thefluid in complementary scroll l6, for the same purpose. Slots 26 and 21may be of a shape other than rectangular, such as curved or of spiralshape, so as-to graduallyopen and close with respect to the rectangularslots 26 and 21..

In operation, and assuming that the engine is operating at low altitudewhere decreased or low pressure rise ratio is required, sleeve valve 2|is so positioned that slots 26 and 26' are in registry and complementaryintake scroll I6 is in operation, with slots 21 and 21' of oppositionintake scroll |1 closed so that it is inoperative. these conditions ofoperation, the complementary intake scroll l6 imparts an initial swirlto the intake fluid in the same direction as the impeller l3 drives thefluid, so that the impeller does less work and hence the pressure riseratio is low.

For higher altitudes, where high pressure rise ratio is required, thesleeve valve 2| is rotated so that its slots 21 are in registry withslots 21', so that opposition intake scroll I1 is in communication withthe interior of supercharger extension l5, while slots 26 and 26' areclosed and complementary intake scroll I6 is inoperative. Under theseconditions, the initial swirl of the intake fluid entering thesupercharger impeller I3 is opposite in direction to the rotation of theimpeller l3, resulting in increase in impeller work and causing increasein the pressure rise ratio.

Rotation of the sleeve valve 2| maybe effected manually by a handleconnected to the link 25 whereby the position of lever 24 may beadjusted to one or the other of the extreme positions to render one orthe other intake scroll I6 or l1 operative and the other inoperative.with this arrangement, intermediate positions or the sleeve Under valve2| may be selected, so that one or the other of the scrolls IE or Hadmits the predominant volume of air, with the other so that theimpeller I 3 is aided or opposed to any desired degree. In this way thepressure rise ratio may be varied from'the minimum at sea level to themaximum at the ceiling of the engine.

Automatic control may be obtained in accordance with changes inaltitude, so that the pressure riseratio is increased progressively withincrease in altitude. One way of eflecting automatic control isillustrated diagrammatically in Fig. 4, where the'sleeve valve rotatinglever 24 is actuated by a piston and valve combination 26, the pistonrod 29 being connected to link 25. A

conventional four-way valve 30 supplies fluid under pressure. such asoil from the engine oil pump connected-to pipe 3|, selectively toopposite sides of piston 32 through pipes 33 and 34, pipe 36 being thedischarge.

Valve 30 is controlled by a gas-filled flexible bellows 36 connectedthereto by link 31 and lever 38. In the position of lever 24 as shown inFig. 4, complementary intake scroll I6 is in operation, and oppositionintake scroll I1 is inoperative, with pressure oil supplied throughvalve 30 from pipe 3| to pipe 33. As the airplane ascends, the decreasein atmospheric pressure permits the gas in the bellows 36 to expand sothat the bellows extends upwardly gradually supplying oil through pipe34 to the opposite side of piston 32 and bleeding of! oil through pipe33.

Accordingly, as the altitude increases, sleeve valve 2| isproportionately rotated to gradually close slots 26 and open slots 21,thereby increasing the pressure rise ratio of the supercharger, until,at the fully open position of sleeve valve 2|, the greatest impellerwork and consequent highest pressure rise ratio isefiected. Upondecrease in altitude, the reverse operation takes place.

Various other automatic controls for the sleeve valve 2| may beobtained, such as those depending upon engine speed, manifold pressure,combinations thereof, with or without altitude compensation, it being;only necessary to substitute for the aneroidcontrol 36 the desiredregulator for controlling the servo-motor arrangement 26-35. Examples ofsuch alternative servo-motor controls are disclosed in said GregoryPatent No. 2,187,737.

Fig. 5 illustrates a modified type of control valve mechanism. In thisform of the invention, the supercharger 46 has a housing 4| providedwith a tubular axial extension 42 with which the scrolls 43 and 44communicate. The scrolls are arranged similarly to the scrolls l6 and I1described above so that opposed swirls will be created in the extension42. The extension 4| has a coaxial hollow extension 46 projectinginwardly and terminating adjacent to the intake end of the impeller 46.

-Within the extension 42 is a tubular sleeve valve 41 for regulating theamount. of air or air and fuel delivered by the scrolls 43 and 44 intothe extension. The sleeve'valve 41 may be adjusted axially by means of apivoted lever 46 connected to the sleeve valve and a link 46 actuatedmanually or automatically as described above.

Another type of valve system for controlling flow from the scrolls tothe supercharger is 11- lustrated in Fig. 6. In this modification,butterfly valves 50 and 5| are arranged in the intake connected by alink 56 which causes one valve 50 or 5| to close when the other isopened. Any

desired flow of fluid through the scrolls 52 and 53 may be obtained byadjusting the valves 50 and 5| to intermediate positions. Adjustment ofthe valves may be accomplished by means of a link 51 connected to thelever 50a and actuated manually or automatically as previouslydescribed.

Although preferred embodiments ofthe invention have been illustrated anddescribed herein, it is to be understood that the invention is notlimited thereby but is susceptible of changes in form and detail withinthe scope of the appended claims.

We claim: a

1. In a supercharger having a rotary impeller in a casing having anaxial extension forming an intake, the combination of a source of supplyof the fluid to be compressed, a substantially tangential inlet 'scrollon said extension and interposed between said source and said intake anddirected oppositely to the direction of rotation of the impeller,whereby the initial swirl imparted to the intake fluid is reversed bythe impeller, a second source of fluid supply, a substantiallytangential inlet scroll on said extension adjacent to thefirst-mentioned scroll and interposed between said second source andsupercharger and directed in the direction of rotation of the impeller.

2. In a supercharger having a rotary impeller in a casing having anaxial intake, the combina-v tion of a source of supply of the fluid tobe compressed, a substantially tangential inlet scroll interposedbetween said source and said intake and directed oppositely to thedirection of rotation of the impeller, a second source of fluid supplyleading to said impeller intake, a substantially tangential inlet scrollinterposed between said second source and said inlet and directed in thedirection of rotation of the impeller, sa 'l scrolls being disposed inside by side relaticnship and substantially coaxial with said intake,and means interposed between said sources and said intake forselectively controlling the supply of fluid from said sources tosaidintake, whereby the direction of movement of the intake fluidrelatively to the direction of the impeller may be regulated.

3. In a supercharger having a rotary impeller in a casing having anaxial extension forming an intake, the combination of a source of supplyof the fluid to be compressed, a, first substantially tangential inletscroll interposed between said source and said intake and directedoppositely to the direction of rotation of the impeller, a second sourceof fluid supply leading to said impeller intake, a second substantiallytangential inlet scroll coaxial with and adjacent to said first scrollinterposed between said second source and said inlet and directed in thedirection of rotation of the impeller, and valve means interposedbetween each of said sources and said intake for controlling the supplyof fluid from each source to said intake.

4. In a supercharger having a rotary impeller in a casing having anaxial intake, the combination of a source of supply of the fluid to becompressed, a first substantially tangential inlet scroll coaxial withsaid intake interposed between said source and said intake and directedoppositely to the direction of rotation of the impeller, a secone sourceof fluid supply leading to said impeller intake, a second substantiallytangential inlet scroll coaxial with said intake and adjacent to saidfirst scroll and interposed between said second source and said inletand directed in the direction of rotation of the impeller, and valvemeans interposed between said sources and said intake for diverting thesupply of fluid from one to the other of said sources.

5. In a supercharger having a rotary impeller in a casing having anaxial intake, the combination of a source of supply of the fluid to becompressed, a substantially tangential inlet scroll interposed betweensaid source and said intake and directed oppositely to the direction ofrotation of the impeller, a second source of fluid supply leading tosaid impeller intake, 9, separate substantially tangential inlet scrollinterposed between said second source and said inlet and directed in thedirection of rotation of the impeller, variable valve means between saidfirst scroll and said intake, variable valve means between said secondscroll and said intake, one of said valve means being normally open andthe other being normally closed, and operating means for said valvemeans, whereby the supply from said scrolls to said intake may beregulated.

'6. In a supercharger having a rotary impeller in a casing havinganaxial intake, the combination of a source of supply of the fluid tobecompressed, a substantially tangential inlet scroll interposed betweensaid source and said intake and directed oppositely to the direction ofrotation of the impeller, a second source of fluid supply'leading tosaid impeller intake, a separate substantially tangential inlet scrollinterposed between said second source and said inlet and directed in thedirection of rotation Of the impeller, variable valve means between saidfirst scroll and said intake, variable valve means between said secondscroll and said intake, one of said valve means being normally open andthe other being normally closed, and common operating means for both ofsaid valve means, whereby one of said valve means is moved toward openposition while the other is moved toward closed position, and

being displaced, whereby'one Port is moved toward closed position whenthe other is moved toward open position to respectively decrease andincrease the supply of fluid from the pair of corresponding scrolls, andmeans for actuating said sleeve valve to selectively vary the supply offluid from said scrolls.

8. In a supercharger having a rotary impeller in a casing having anaxial intake, the combination of a hollow extension on said casing inalignment with said intake,-a pair of scrolls in side by siderelationship on said extension and communicating with said intake, oneof said scrolls being directed oppositely" to the direction of rota-'tion of said impeller and the other scroll being directed in thedirection of rotation of'said impeller, and valve means for regulatingthe flow of air through said scrolls.

EUGENE W. WASIELEWSKI. ALFRED T. GREGORY.

